Oscar j



(No Model.)

O J BEALE WORM AND WORM SHAFT.

Patented Apr. 12, 1892.

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WITNESSES t screw-thread cl2, all as shown in Fig. 5.'

UNITED STATES PATENT `Y OEEICE.

OSCAR J. BEALE, OF PROVIDENCE, RI-IODE ISLAND, ASSIGNOR TO THE BROVN da SHARPE MANUFACTURING COMPANY, OF SAME PLACE.

WORM AND WORM-SHAFT.

SPECIFICATION forming part of Letters Patent No. 472,517, dated April 12, 1892.

Application led July 22, 1891.

To @ZZ whom/.it may concern:

Be it known that I, OSCAR J. REALE, of the city and county of Providence, in the State of Rhode Island,have invented certain new and useful Improvements in Worms and Worm- Shafts; and I do hereby declare the following specification,taken in connection with the accompanying drawings, forming a part of the same, to be a full, clear, and exact description thereof.

My invention relates to improvements in worms and worm-shafts for imparting motion to a co-operatin g worm-wheel; and the object of my invention is to provide for an adjustment of the .parts to take up wear and prevent backlash without changing the distance between the axis of the worm-shaft and the axis of the worm-wheel.

To that end my invention consists in the combinations and arrangements of parts hereinafter described.

Referring to the drawings, Figure l is a front view, partly in section, of my improved worm-shaft and worms, in combination with the co-operating worm-wheel, a portion of the teeth on which are shown in section. Fig. 2 is a Section on the line x a: of Fig. l. Fig. 3 is a central longitudinal section of the two worms detached from the worm-shaft. Fig. 4 is an end view of one of the worms. Fig. 5 is a view, partly in section, of the worm-shaft; and Fig. 6 represents a screw-threaded pin for expanding the worm-shaft to hold the worms. thereon in the manner shown in the drawings.

A represents a suitable frame for supporting the parts.

B represents the worm -shaft, and C the worm -wheel shaft. The worm-shaft B is mounted in bearings h, inserted in the frame, and is provided with a collar c, and at its free end with an exterior screw-thread c and check-nuts c2 for taking up end-play. The end of the worm-shaft B is bored out to form a central recess d, the inner end of said recess being tapering, as at d', and the outer end of said recess being provided with an inteiipr 1e worm-shaft B is also provided at the point where the worm or worms are to be secured Serial No. 400,277. (No model.)

`with an external screwthread e, and also with a series of Vslits or slots e', which extend through to the recess d, as shown in Fig. 2.

D represents the worm, which is of tapering form, as shown in the drawings, and which is provided with the usual worm-thread d3. The worm D is also provided with an interior screw-thread f for engaging the screw-thread e' on the worm-shaft, both of the threads c and f beingof the same pitch as the wormkthread cl3.

Preferably I employ two tapering worms D, arranged as shown in the drawings, each of said worms being provided with an interior screw-thread f to engage the screw-thread e on the worm-shaft. To hold the worm or worms D firmly upon the worm-shaft and so that th ey will rotate therewith, a screw-threaded pin E is fitted to enter the recess CZ in said shaft, said pin being tapered at its end, as at cto fit the tapering portion d of said recess, and being provided with a screw-thread e3 to engage the screw-thread d2 in said recess. The worm or worms D having been screwed onto the shaft B, it will be seen that byturning the pin E in a direction to force its tapering end into the tapering recess in the shaft the Walls of the hollow portion of said shaft will be expanded, so as to rmly hold the worm or worms upon the shaft, such expansion being permitted by reason of the slits e.

The worm-wheel F is secured 'to its shaft C in the usual manner in a position to be engaged and operated by the worm or worms D upon the worm-shaft.

The parts when new are to be assembled in the position shown in Fig. 1that is, with the two worms D separated from each other to the fullest extent. If now after a period of use either the worm or the worm-wheel, or

both, become worn, such wear may be readily taken up in the following manner: By turning the screw-threaded pin E in a direction to withdraw the same the worms D will, by reason of the contraction of the split portion of the worm-shaft, be released, so that they -may be readily turned upon said shaft, and

by turning said worms they will, by reason of the screw-threaded connection between said worms and shaft, be made to approach each IOO other, which will result, as will be apparent, in bringing portions of the worm which are of larger diameter in contact with the wormwheel, thus taking up the wear. When the worms have been thus adjusted, the screwthreaded pin is again screwed in, so that its tapering end will expand the split portion of the shaft, and thus hold the worms firmly in their adjusted position. It will be seen that by the adjustment thus elected the distance between the axis of the worm-shaft and the axis of the worm-wheel is in no way changed or effected, and, further, that by reason of the fact that the screwthreads e f on the wormshai't and worms, respectively, are of the saine pitch as the worin-threads said worm-threads upon the two worms will always match with each other, and so that one forms practically a continuation of the other, and both of said worm-threads will likewise always match with the teeth of the worm-wheel in any and all adjusted positions of the worms.

- If desired, only one tapering worm need be employed, the adjustment of which will take up the wear in the same manner as above de scribed, although, as stated, I prefer to employ two such tapering worms adjustable toward and from cach other lengthwise ol the worm-shaft, as thereby a greater extent of contact with the worm-wheel is secured.

XVhat I claim as my invention, and desire to secure by Letters Patent, is

l. The combination, with a worm-shaft, of two tapering worms mounted upon said shaft,

'both said shaft and worms being provided with screw-threads of the same pitch as the worm-thread, whereby said worms may be adjusted lengthwise of said shaft without changing the relation of the worm-threads thereon, and means for holding said worms in any adj usted position upon said shaft, substantially as described.

2. The combination of a worm-shaft provided with a central recess d, tapering at its end, and with slots e', a tapering worm mounted upon said worm-shaft, and a screw-threaded pin D, fitted to enter the recess d in said wormshaft and provided with a taperi ng end, whereby said tapering worm may be irmly held in position upon said worm-shaft, substantially as described.

OSCAR J. REALE.

lVitnesses:

W. H. THURsToN, S. J. MURPHY. 

